using Microsoft.EntityFrameworkCore;

namespace BudgetApp.Components.Pages;

public partial class Settings
{
    private static readonly string AppVersion =
        typeof(Program).Assembly.GetName().Version?.ToString(3) ?? "0.0.0";

    private ChangePasswordForm _passwordForm = new();
    private bool _passwordSuccess;
    private string? _passwordError;
    private bool _confirmingDelete;
    private string _deletePassword = string.Empty;
    private string? _deleteError;
    private bool _confirmingReset;
    private string _resetConfirmation = string.Empty;
    private string _resetPassword = string.Empty;
    private string? _resetError;
    private bool _resetSuccess;

    private async Task ChangePassword()
    {
        _passwordSuccess = false;
        _passwordError = null;

        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
        var userIdClaim = authState.User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value;
        if (userIdClaim is null) return;

        var user = await UserManager.FindByIdAsync(userIdClaim);
        if (user is null) return;

        var result =
            await UserManager.ChangePasswordAsync(user, _passwordForm.CurrentPassword, _passwordForm.NewPassword);

        if (result.Succeeded)
        {
            _passwordSuccess = true;
            _passwordForm = new ChangePasswordForm();
        }
        else
        {
            _passwordError = string.Join(" ", result.Errors.Select(e => e.Description));
        }
    }

    private async Task DeleteAccount()
    {
        _deleteError = null;

        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
        var userIdClaim = authState.User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value;
        if (userIdClaim is null) return;

        var user = await UserManager.FindByIdAsync(userIdClaim);
        if (user is null) return;

        var passwordValid = await UserManager.CheckPasswordAsync(user, _deletePassword);
        if (!passwordValid)
        {
            _deleteError = "Incorrect password.";
            return;
        }

        // Delete all user data explicitly in correct dependency order
        await DbContext.Transactions
            .Where(t => t.Account.UserId == userIdClaim)
            .ExecuteDeleteAsync();

        await DbContext.Accounts
            .Where(a => a.UserId == userIdClaim)
            .ExecuteDeleteAsync();

        await DbContext.Categories
            .Where(c => c.UserId == userIdClaim)
            .ExecuteDeleteAsync();

        // Delete identity user
        await UserManager.DeleteAsync(user);
        await SignInManager.SignOutAsync();

        Navigation.NavigateTo("/login", forceLoad: true);
    }

    private void CancelDelete()
    {
        _confirmingDelete = false;
        _deletePassword = string.Empty;
        _deleteError = null;
    }

    private async Task ResetData()
    {
        _resetError = null;
        _resetSuccess = false;

        var authState = await AuthStateProvider.GetAuthenticationStateAsync();
        var userIdClaim = authState.User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value;
        if (userIdClaim is null) return;

        var user = await UserManager.FindByIdAsync(userIdClaim);
        if (user is null) return;

        if (!string.Equals(_resetConfirmation?.Trim(), "I UNDERSTAND", StringComparison.Ordinal))
        {
            _resetError = "Please type 'I UNDERSTAND' exactly to confirm.";
            return;
        }

        var passwordValid = await UserManager.CheckPasswordAsync(user, _resetPassword);
        if (!passwordValid)
        {
            _resetError = "Incorrect password.";
            return;
        }

        await DbContext.Transactions
            .Where(t => t.Account.UserId == userIdClaim)
            .ExecuteDeleteAsync();

        await DbContext.Accounts
            .Where(a => a.UserId == userIdClaim)
            .ExecuteDeleteAsync();

        await DbContext.Categories
            .Where(c => c.UserId == userIdClaim)
            .ExecuteDeleteAsync();

        _confirmingReset = false;
        _resetConfirmation = string.Empty;
        _resetPassword = string.Empty;
        _resetSuccess = true;

        AppState.NotifyAccountsChanged();
    }

    private void CancelReset()
    {
        _confirmingReset = false;
        _resetConfirmation = string.Empty;
        _resetPassword = string.Empty;
        _resetError = null;
    }

    private sealed class ChangePasswordForm
    {
        [System.ComponentModel.DataAnnotations.Required(ErrorMessage = "Current password is required")]
        public string CurrentPassword { get; set; } = string.Empty;

        [System.ComponentModel.DataAnnotations.Required(ErrorMessage = "New password is required")]
        [System.ComponentModel.DataAnnotations.MinLength(8, ErrorMessage = "Password must be at least 8 characters")]
        public string NewPassword { get; set; } = string.Empty;

        [System.ComponentModel.DataAnnotations.Required(ErrorMessage = "Please confirm your new password")]
        [System.ComponentModel.DataAnnotations.Compare(nameof(NewPassword), ErrorMessage = "Passwords do not match")]
        public string ConfirmNewPassword { get; set; } = string.Empty;
    }
}